W32.HLLW.Henpeck

SUMMARY

W32.HLLW.Henpeck is a worm that is written in Visual Basic. The worm spreads using MSN Messenger, and it is capable of downloading updates to itself from a Web site. The worm appears to originate from Norway, and it uses the file name BR2002.exe.

NOTE: At the time of writing, it was no longer possible to download any of the files from the Web site.

Protection

• Virus Definitions (LiveUpdate™ Weekly) October 9, 2002
• Virus Definitions (Intelligent Updater) October 9, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Low

Distribution

• Distribution Level: Medium

TECHNICAL DETAILS

When this worm is executed, it does the following:

First, it displays a small window that has two buttons: Generate and Quit. If you click Generate, a key is displayed in the window. This appears to be an attempt to disguise itself as a CD key generator.

Next, the worm sends the following message to all contacts in the MSN Messenger for Windows contact list:

Hey!! Could you please check this program for me? :)  I made it myself and want people to test it. Its a readme with the program that explains what it does! <removed link> <- There you can download it! give me advices on what to upgrade please!!

NOTE: The link no longer works. Currently, if you click the link, a page appears with the message that says that you are not authorized to view the Web page.

Next, the worm attempts to download two additional files from a Web site. If it is successful, the files are saved as C:Update35784.exe and C:Hehe2397824.exe. Norton AntiVirus detects these two Trojans as W32.IRCBot.Gen. However, at the time that this document was written, it was no longer possible to download the two files.

If C:Hehe2397824.exe is executed it does the following:

• It copies itself as the file %windir%WinUpdat.exeupdate.ur.address.
• It creates the value
  
  WinUpdat %windir%WinUpdat.exeupdate.ur.address
  
  in the registry key
  
  HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
  
  so that it is executed each time that you start Windows.

Finally, the worm tries to find what appears to be CD keys that belong to the game named Half-Life and to an add-on for the game named Counterstrike. The worm looks for them in these locations:

HKEY_CURRENT_USERSoftwareValveHalf-LifeSettingsKey
HKEY_CURRENT_USERSoftwareValveCounterStrikeSettingsKey

If the worm finds the keys, it includes them in an MSN message that it sends to the hacker.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

REMOVAL

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions.
2. Run a full system scan, and delete all files that are detected as W32.HLLW.Henpeck.
3. Delete the value
   
   WinUpdat
   
   from the registry key
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   

For details on how to do this, read the following instructions.

To update the virus definitions:
All virus definitions receive full quality assurance testing by Symantec Security Response before being posted to our servers. There are two ways to obtain the most recent virus definitions:

• Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
• Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
  
  Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

To scan for and delete the infected files:

1. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
   • Norton AntiVirus consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec enterprise antivirus products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
2. Run a full system scan.
3. If any files are detected as infected with W32.HLLW.Henpeck, click Delete.

To remove the value from the registry:

CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

1. Click Start, and click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the key
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, if it exists, delete the value
   
   WinUpdat
   
5. Exit the Registry Editor.